Atomizer for internal combustion engines



Jan. 26, 1960 2. KOKTAN ATOMIZER FOR INTERNAL COMBUSTION ENGINES FiledFeb. 12, 1958 INVENTOR. Zden fioA zam United States Patent f ATOMIZERFOR INTERNAL COMBUSTION ENGINES Zdenk Koktau, Libcice upon Vltava,Czechoslovakia, as-

signor to Vyzkumny a zkusebni letecky ustav, Prague, CzechoslovakiaApplication February 12, 1958, Serial No. 714,758

Claims priority, application Czechoslovakia February 18, 1957 6 Claims.(Cl. 261-84) The present invention relates to a device for producing acombustible mixture or charge for piston type internal combustionengines and particularly for aircraft engines provided withsuperchargers.

It is an object of this invention to provide a device of the describedcharacter which ensures perfect atomization of the fuel, is easilyadjustable, operates reliably in all flight positions and is simple andreliable in service.

At present, piston-type internal combustion engines generally use eithercarburetors or injection pumps. Both these fuel feeding systemshave'numerous operating disadvantages, such as, imperfect atomization ofthe fuel, inferior acceleration and starting of the engines, possibilityof icing and, in aircraft engines, interruption of the'feeding of fuelwhen performing acrobatics. There are further drawbacks relating tomanufacturing costs and difficulties during manufacture, and to thecomplexity and lack of sturdiness of the existing systems.

In accordance with this invention a rotating body is provided with anumber of substantially radial channels terminating in nozzles andacting as a centrifugal pump. Such body may be supportedby the shaft ofthe rotor of the engine supercharger. The fuel is atomized either by thenozzles alone or by pan shaped discs or by a combination of nozzles anddiscs. Thus perfect and uniform atomizing of the fuel within a widerange is achieved for any required condition of the engine. The outputof the engine is increased and the performance is more economical andreliable, as a more uniform distribution of the combustion mixture intothe respective engine cylinders is achieved.

Since the atomization of the fuel takes place in front of the rotor ofthe supercharger, the temperature of the air drawn into thesupercharger. is decreased and the operating safety and independenceupon the position of the aircraft is increased, so that this device isparticularly suitable for aircraft performing acrobatics.

Illustrative embodiments of this invention are shown by way of examplein the accompanying drawing, where Fig. 1 is a longitudinal sectionalview of an atomizer with nozzles, Fig. 2 is a similar view of anatomizer with nozzles and a pan shaped disc for atomization, and Fig. 3is a similar view of a detail of a modified pan-shaped disc providedwith an additional blower for the supply of air.

Referring to Fig. 1, it will be seen that a centrifugal atomizerembodying the invention comprises a body 1 provided with a cavity 4,from which a number of substantially radial channels 2 open outwardly sothat, during rotation of the body 1, centrifugal force drives the fuelmixture along channels 2 and the latter act as a centrifugal pump. Inthe embodiment according to Fig. 1 there are three rows of channels 2,and each channel is provided near its outer extremity with a nozzle 3imparting a whirling movement to the mixture and with a small adjacentchamber terminating in a discharge opening 11. A gap 12 for passage of asupply of air is 2,922,631 Patented Jan. 26, 1960 left between a fuelsupply tube 5 and the body 1, with the tube 5 terminating in theneighbourhood of the row of channels 2 disposed closest to the inner endof the cavity 4. Shoulders 15 are provided within the cavity 4 forpartly separating the inner ends of the channels 2 of the several rows.The body 1 is intended to be attached to the rotor of the enginesupercharger.

In the embodiment of Fig. 2, the cavity 4a within the body 1a isprovided with a radial partition wall 14 dividing this space into twoparts, one of which serves for the supply of fuel, and the other for thesupply of air. The space for the supply of fuel is provided with a rowof channels 2a with nozzles 3a at their outer ends and further withchannels 6 opening outwardly into an annular space between the body 1aand a pan shaped disc 7 having a cone-shaped inner surface and beingattached to'the body 1a. Radial channels 13 extend outwardly from theother space, that is, from the space in front of wall 14, and open intothe same annular space between body 1a and disc 7 to supply air to thatannular space.

In place of the channels 13, a ring of special blades 9 may be providedin the pan shaped disc 7 to provide a blower for sucking air into theannular space between the body and disc 7, as in Fig. 3.

The body In of the centrifugal atomizer of Fig. 2 is supported by theshaft of the rotor 8 of the engine supercharger, with which it iscoaxial.

The centrifugal force transmits to the fuel passing through the channels2 the energy required for atomization. The fuel is driven from thechannels 2 into the nozzles 3 which impart a whirling movement to themixture, and the latter passes the chamber 10 and is atomized whenleaving the discharge opening 11. When the rate at which the fuel issupplied increases and the channels 2 of the innermost row are no moreable to pass this increased rate of feed, the fuel passes over theshoulder 15 to the adjacent row of channels. This arrangement permitsthe selection of suitable cross sections for the nozzles in accordancewith the required amount of atomized fuel. The attainment of perfectatomization is assisted by the air sucked through the space 12.

In the arrangement of Fig. 2, the part of the fuel passing throughchannels 2a is atomized by nozzles 3, for example, during operation atslow engine speeds, and the remaining fuel passing through channels 6 isatomized at the edge of the rotated pan shaped disc 7.

The atomizing by the pan shaped disc 7 is achieved by the fuel beingthrown by centrifugal force from channels 6 against the conical innerwall surface of disc 7, whereupon the fuel proceeds in the direction ofthe increasing radius, and hence increasing centrifugal force, to theedge of the disc 7, whereby the thickness of the fuel film steadilydecreases until it forms, on the edge of the disc, a narrow film whichdisperses into a fine mist. The air supplied either through the channels13 or by the small blower blades 9 arranged in the disc 7 assists in theatomization of the fuel delivered through channels 6. It is apparentthat the elements described with reference to Figs. 1, 2 or 3 may becombined.

The centrifugal atomizer according to this invention is primarilysuitable for piston-type internal combustion engines and particularlyfor aircraft engines provided ing outwardly from said cavity, thechannels of at least the one of said rows closest to the rotor havingnozzles adjacent their outer ends operative to impart a whirlingmovement to the fuel driven along the related channels by centrifugalforce, each channel provided with a nozzle further having a smallchamber into which the nozzle opens and a discharge openingcommunicating said chamber with the space outside of said body, and saidfuel supply tube being spaced radially from the surface of said cavityto define an annular space tberebetween forming at least part of meanssupplying air for admixture with the fuel supplied by said tube.

2. An atomizer as in claim 1; wherein said fuel supply tube terminatesadjacent said one row of the channels and all of the latter have saidnozzles; and wherein said surface of the cavity has radially inwarddirected shoulders partly obstructing said annular space at locationsbetween the successive rows of channels so that the fuel issuing fromsaid supply tube is initially discharged, along with air from saidannular space, through the channels ofsaid one row until the rate offuel supply exceeds the flow capacity of the channels of said one row,whereupon the excess fuel backs-up past the shoulder between said onerow and the next adjacent row for discharge, along with air from saidannular space, through the channels of said next adjacent row.

3. An atomizer as in claim 1; further comprising a radial partition wallextending between said surface of the cavity and said fuel supply tubeat a location intermediate the opposite ends of said cavity to dividethe latter into an inner compartment with which said channels and fuelsupply tube communicate and an outer compartment receiving the supply ofair, said body having at least one additional row of radial channelsextending from said outer compartment and opening at the outer surfaceof the body for the discharge of air, and a panshaped disc secured tosaid body and having a conical inner surface extending around, andspaced radially from a portion of the outer surface of the body andincreasing in diameter in the axial direction toward the superchargerrotor so that air discharged from said additional row of channels isdeflected by said inner surface in the axial direction toward the rotorfor mixing with the fuel issuing from the first mentioned rows ofchannels.

4. An atomizer as in claim 1; further comprising a pan-shaped discsecured'to said body and having-a conical inner surface extendingaround, and spaced radially from a portion of the outer surface of thebody, with said conical inner surface of the disc increasing in diameterin the axial direction toward the rotor so that fuel being dischargedfrom at least some of said channels impinges against said inner surfaceof the disc and travels axially along said inner surface for release, asa fine mist, at the relatively large diameter edge thereof; and whereinsaid means supplying air for admixture with the fuel discharges thesupplied air between said outer surface of the body and said innersurface of the pan-shaped disc.

5. An atomizer as in claim 4; wherein said means supplying air includesa radial partition wall extending between said tube and said surface ofthe cavity to divide the latter into an inner compartment with whichsaid channels and fuel supply tube communicate and an outer compartmentreceiving a supply of air, and an additional row of radial channels insaid body extending from said outer compartment and opening at saidportion of the outer surface of said body so that air dischargedradially through said additional channels is deflected by said innersurface of the disc in the axial direction toward said edge of the disc.

6. An atomizer as in claim 4; wherein said means supplying air furtherincludes a circular row of blades on said pan-shaped disc forming an airblower discharging between said outer surface of the body and said innersurface of the disc.

References Cited in the file of this patent UNITED STATES PATENTS

